In general, an industrial robot, as a kind of robot is a machine performing works in a working field instead of a human being. The robot can replace men's works in bad fields by abnormal temperature, humidity, and noise and in dangerous fields such as a nuclear power plant or a coal mine.
The industrial robot is applied in various fields such as a semiconductor device fabricating process or an automated system. Especially, the industrial robot is used to increase productivity even in an automobile fabricating process, in which the industrial robot performs a required operation by moving an object of working by a conveyor or etc.
In performing the operations required to the moving object of working, the industrial robot has functions such as synchronization with the conveyor, vision detection, and tracking functions.
Said functions are used in a low operation frequency so as to enhance a stability of a system. At this time, in case of a robot having high output, large torque is required at the time of tracking the object of working and its operational performance is degraded by its own mass or inertia of moment of the mass.
Accordingly, since the above functions cannot rapidly respond to a field situation having a high frequency such as rapid change, the above functions are limited mainly to an object of working having a low frequency that moves with a constant velocity.
To solve the problems, a robot having a redundant degree of freedom is being developed to enhance an operation frequency of a robot. A 1+6 robot developed in the Ford Company is devised and tested to perform work such as an assembly for the moving object of working by attaching the robot having 6 degrees of freedom to a linear movement device having one degree of freedom.
That is, the assembly operation for the moving object was performed by attaching the robot to the linear movement device of one degree of freedom. However, since the additional linear movement device of one degree of freedom has to be moved by adjusting the robot to a conveyor, a lot of driving forces are required and a responsive performance of a system is degraded.